package t1;

import java.util.AbstractQueue;


    interface USB {
        double USBVERSION=3.0;
        public abstract void startwork();
        public abstract void stopwork();
}
     class KeyBord implements USB {
     public void startwork(){
      System.out.println("键盘开始工作");
    }
      public void stopwork() {
      System.out.println("键盘停止工作");
   }
}
    class Mouse implements USB {
      public void startwork(){
            System.out.println("鼠标开始工作");
    }
        public void stopwork(){
            System.out.println("鼠标停止工作");
    }
}
